xref: /linux/drivers/target/iscsi/iscsi_target_util.c (revision 4b132aacb0768ac1e652cf517097ea6f237214b9)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*******************************************************************************
3  * This file contains the iSCSI Target specific utility functions.
4  *
5  * (c) Copyright 2007-2013 Datera, Inc.
6  *
7  * Author: Nicholas A. Bellinger <nab@linux-iscsi.org>
8  *
9  ******************************************************************************/
10 
11 #include <linux/list.h>
12 #include <linux/sched/signal.h>
13 #include <net/ipv6.h>         /* ipv6_addr_equal() */
14 #include <scsi/scsi_tcq.h>
15 #include <scsi/iscsi_proto.h>
16 #include <target/target_core_base.h>
17 #include <target/target_core_fabric.h>
18 #include <target/iscsi/iscsi_transport.h>
19 
20 #include <target/iscsi/iscsi_target_core.h>
21 #include "iscsi_target_parameters.h"
22 #include "iscsi_target_seq_pdu_list.h"
23 #include "iscsi_target_datain_values.h"
24 #include "iscsi_target_erl0.h"
25 #include "iscsi_target_erl1.h"
26 #include "iscsi_target_erl2.h"
27 #include "iscsi_target_tpg.h"
28 #include "iscsi_target_util.h"
29 #include "iscsi_target.h"
30 
31 extern struct list_head g_tiqn_list;
32 extern spinlock_t tiqn_lock;
33 
34 int iscsit_add_r2t_to_list(
35 	struct iscsit_cmd *cmd,
36 	u32 offset,
37 	u32 xfer_len,
38 	int recovery,
39 	u32 r2t_sn)
40 {
41 	struct iscsi_r2t *r2t;
42 
43 	lockdep_assert_held(&cmd->r2t_lock);
44 
45 	WARN_ON_ONCE((s32)xfer_len < 0);
46 
47 	r2t = kmem_cache_zalloc(lio_r2t_cache, GFP_ATOMIC);
48 	if (!r2t) {
49 		pr_err("Unable to allocate memory for struct iscsi_r2t.\n");
50 		return -1;
51 	}
52 	INIT_LIST_HEAD(&r2t->r2t_list);
53 
54 	r2t->recovery_r2t = recovery;
55 	r2t->r2t_sn = (!r2t_sn) ? cmd->r2t_sn++ : r2t_sn;
56 	r2t->offset = offset;
57 	r2t->xfer_len = xfer_len;
58 	list_add_tail(&r2t->r2t_list, &cmd->cmd_r2t_list);
59 	spin_unlock_bh(&cmd->r2t_lock);
60 
61 	iscsit_add_cmd_to_immediate_queue(cmd, cmd->conn, ISTATE_SEND_R2T);
62 
63 	spin_lock_bh(&cmd->r2t_lock);
64 	return 0;
65 }
66 
67 struct iscsi_r2t *iscsit_get_r2t_for_eos(
68 	struct iscsit_cmd *cmd,
69 	u32 offset,
70 	u32 length)
71 {
72 	struct iscsi_r2t *r2t;
73 
74 	spin_lock_bh(&cmd->r2t_lock);
75 	list_for_each_entry(r2t, &cmd->cmd_r2t_list, r2t_list) {
76 		if ((r2t->offset <= offset) &&
77 		    (r2t->offset + r2t->xfer_len) >= (offset + length)) {
78 			spin_unlock_bh(&cmd->r2t_lock);
79 			return r2t;
80 		}
81 	}
82 	spin_unlock_bh(&cmd->r2t_lock);
83 
84 	pr_err("Unable to locate R2T for Offset: %u, Length:"
85 			" %u\n", offset, length);
86 	return NULL;
87 }
88 
89 struct iscsi_r2t *iscsit_get_r2t_from_list(struct iscsit_cmd *cmd)
90 {
91 	struct iscsi_r2t *r2t;
92 
93 	spin_lock_bh(&cmd->r2t_lock);
94 	list_for_each_entry(r2t, &cmd->cmd_r2t_list, r2t_list) {
95 		if (!r2t->sent_r2t) {
96 			spin_unlock_bh(&cmd->r2t_lock);
97 			return r2t;
98 		}
99 	}
100 	spin_unlock_bh(&cmd->r2t_lock);
101 
102 	pr_err("Unable to locate next R2T to send for ITT:"
103 			" 0x%08x.\n", cmd->init_task_tag);
104 	return NULL;
105 }
106 
107 void iscsit_free_r2t(struct iscsi_r2t *r2t, struct iscsit_cmd *cmd)
108 {
109 	lockdep_assert_held(&cmd->r2t_lock);
110 
111 	list_del(&r2t->r2t_list);
112 	kmem_cache_free(lio_r2t_cache, r2t);
113 }
114 
115 void iscsit_free_r2ts_from_list(struct iscsit_cmd *cmd)
116 {
117 	struct iscsi_r2t *r2t, *r2t_tmp;
118 
119 	spin_lock_bh(&cmd->r2t_lock);
120 	list_for_each_entry_safe(r2t, r2t_tmp, &cmd->cmd_r2t_list, r2t_list)
121 		iscsit_free_r2t(r2t, cmd);
122 	spin_unlock_bh(&cmd->r2t_lock);
123 }
124 
125 static int iscsit_wait_for_tag(struct se_session *se_sess, int state, int *cpup)
126 {
127 	int tag = -1;
128 	DEFINE_SBQ_WAIT(wait);
129 	struct sbq_wait_state *ws;
130 	struct sbitmap_queue *sbq;
131 
132 	if (state == TASK_RUNNING)
133 		return tag;
134 
135 	sbq = &se_sess->sess_tag_pool;
136 	ws = &sbq->ws[0];
137 	for (;;) {
138 		sbitmap_prepare_to_wait(sbq, ws, &wait, state);
139 		if (signal_pending_state(state, current))
140 			break;
141 		tag = sbitmap_queue_get(sbq, cpup);
142 		if (tag >= 0)
143 			break;
144 		schedule();
145 	}
146 
147 	sbitmap_finish_wait(sbq, ws, &wait);
148 	return tag;
149 }
150 
151 /*
152  * May be called from software interrupt (timer) context for allocating
153  * iSCSI NopINs.
154  */
155 struct iscsit_cmd *iscsit_allocate_cmd(struct iscsit_conn *conn, int state)
156 {
157 	struct iscsit_cmd *cmd;
158 	struct se_session *se_sess = conn->sess->se_sess;
159 	int size, tag, cpu;
160 
161 	tag = sbitmap_queue_get(&se_sess->sess_tag_pool, &cpu);
162 	if (tag < 0)
163 		tag = iscsit_wait_for_tag(se_sess, state, &cpu);
164 	if (tag < 0)
165 		return NULL;
166 
167 	size = sizeof(struct iscsit_cmd) + conn->conn_transport->priv_size;
168 	cmd = (struct iscsit_cmd *)(se_sess->sess_cmd_map + (tag * size));
169 	memset(cmd, 0, size);
170 
171 	cmd->se_cmd.map_tag = tag;
172 	cmd->se_cmd.map_cpu = cpu;
173 	cmd->conn = conn;
174 	cmd->data_direction = DMA_NONE;
175 	INIT_LIST_HEAD(&cmd->i_conn_node);
176 	INIT_LIST_HEAD(&cmd->datain_list);
177 	INIT_LIST_HEAD(&cmd->cmd_r2t_list);
178 	spin_lock_init(&cmd->datain_lock);
179 	spin_lock_init(&cmd->dataout_timeout_lock);
180 	spin_lock_init(&cmd->istate_lock);
181 	spin_lock_init(&cmd->error_lock);
182 	spin_lock_init(&cmd->r2t_lock);
183 	timer_setup(&cmd->dataout_timer, iscsit_handle_dataout_timeout, 0);
184 
185 	return cmd;
186 }
187 EXPORT_SYMBOL(iscsit_allocate_cmd);
188 
189 struct iscsi_seq *iscsit_get_seq_holder_for_datain(
190 	struct iscsit_cmd *cmd,
191 	u32 seq_send_order)
192 {
193 	u32 i;
194 
195 	for (i = 0; i < cmd->seq_count; i++)
196 		if (cmd->seq_list[i].seq_send_order == seq_send_order)
197 			return &cmd->seq_list[i];
198 
199 	return NULL;
200 }
201 
202 struct iscsi_seq *iscsit_get_seq_holder_for_r2t(struct iscsit_cmd *cmd)
203 {
204 	u32 i;
205 
206 	if (!cmd->seq_list) {
207 		pr_err("struct iscsit_cmd->seq_list is NULL!\n");
208 		return NULL;
209 	}
210 
211 	for (i = 0; i < cmd->seq_count; i++) {
212 		if (cmd->seq_list[i].type != SEQTYPE_NORMAL)
213 			continue;
214 		if (cmd->seq_list[i].seq_send_order == cmd->seq_send_order) {
215 			cmd->seq_send_order++;
216 			return &cmd->seq_list[i];
217 		}
218 	}
219 
220 	return NULL;
221 }
222 
223 struct iscsi_r2t *iscsit_get_holder_for_r2tsn(
224 	struct iscsit_cmd *cmd,
225 	u32 r2t_sn)
226 {
227 	struct iscsi_r2t *r2t;
228 
229 	spin_lock_bh(&cmd->r2t_lock);
230 	list_for_each_entry(r2t, &cmd->cmd_r2t_list, r2t_list) {
231 		if (r2t->r2t_sn == r2t_sn) {
232 			spin_unlock_bh(&cmd->r2t_lock);
233 			return r2t;
234 		}
235 	}
236 	spin_unlock_bh(&cmd->r2t_lock);
237 
238 	return NULL;
239 }
240 
241 static inline int iscsit_check_received_cmdsn(struct iscsit_session *sess, u32 cmdsn)
242 {
243 	u32 max_cmdsn;
244 	int ret;
245 
246 	/*
247 	 * This is the proper method of checking received CmdSN against
248 	 * ExpCmdSN and MaxCmdSN values, as well as accounting for out
249 	 * or order CmdSNs due to multiple connection sessions and/or
250 	 * CRC failures.
251 	 */
252 	max_cmdsn = atomic_read(&sess->max_cmd_sn);
253 	if (iscsi_sna_gt(cmdsn, max_cmdsn)) {
254 		pr_err("Received CmdSN: 0x%08x is greater than"
255 		       " MaxCmdSN: 0x%08x, ignoring.\n", cmdsn, max_cmdsn);
256 		ret = CMDSN_MAXCMDSN_OVERRUN;
257 
258 	} else if (cmdsn == sess->exp_cmd_sn) {
259 		sess->exp_cmd_sn++;
260 		pr_debug("Received CmdSN matches ExpCmdSN,"
261 		      " incremented ExpCmdSN to: 0x%08x\n",
262 		      sess->exp_cmd_sn);
263 		ret = CMDSN_NORMAL_OPERATION;
264 
265 	} else if (iscsi_sna_gt(cmdsn, sess->exp_cmd_sn)) {
266 		pr_debug("Received CmdSN: 0x%08x is greater"
267 		      " than ExpCmdSN: 0x%08x, not acknowledging.\n",
268 		      cmdsn, sess->exp_cmd_sn);
269 		ret = CMDSN_HIGHER_THAN_EXP;
270 
271 	} else {
272 		pr_err("Received CmdSN: 0x%08x is less than"
273 		       " ExpCmdSN: 0x%08x, ignoring.\n", cmdsn,
274 		       sess->exp_cmd_sn);
275 		ret = CMDSN_LOWER_THAN_EXP;
276 	}
277 
278 	return ret;
279 }
280 
281 /*
282  * Commands may be received out of order if MC/S is in use.
283  * Ensure they are executed in CmdSN order.
284  */
285 int iscsit_sequence_cmd(struct iscsit_conn *conn, struct iscsit_cmd *cmd,
286 			unsigned char *buf, __be32 cmdsn)
287 {
288 	int ret, cmdsn_ret;
289 	bool reject = false;
290 	u8 reason = ISCSI_REASON_BOOKMARK_NO_RESOURCES;
291 
292 	mutex_lock(&conn->sess->cmdsn_mutex);
293 
294 	cmdsn_ret = iscsit_check_received_cmdsn(conn->sess, be32_to_cpu(cmdsn));
295 	switch (cmdsn_ret) {
296 	case CMDSN_NORMAL_OPERATION:
297 		ret = iscsit_execute_cmd(cmd, 0);
298 		if ((ret >= 0) && !list_empty(&conn->sess->sess_ooo_cmdsn_list))
299 			iscsit_execute_ooo_cmdsns(conn->sess);
300 		else if (ret < 0) {
301 			reject = true;
302 			ret = CMDSN_ERROR_CANNOT_RECOVER;
303 		}
304 		break;
305 	case CMDSN_HIGHER_THAN_EXP:
306 		ret = iscsit_handle_ooo_cmdsn(conn->sess, cmd, be32_to_cpu(cmdsn));
307 		if (ret < 0) {
308 			reject = true;
309 			ret = CMDSN_ERROR_CANNOT_RECOVER;
310 			break;
311 		}
312 		ret = CMDSN_HIGHER_THAN_EXP;
313 		break;
314 	case CMDSN_LOWER_THAN_EXP:
315 	case CMDSN_MAXCMDSN_OVERRUN:
316 	default:
317 		cmd->i_state = ISTATE_REMOVE;
318 		iscsit_add_cmd_to_immediate_queue(cmd, conn, cmd->i_state);
319 		/*
320 		 * Existing callers for iscsit_sequence_cmd() will silently
321 		 * ignore commands with CMDSN_LOWER_THAN_EXP, so force this
322 		 * return for CMDSN_MAXCMDSN_OVERRUN as well..
323 		 */
324 		ret = CMDSN_LOWER_THAN_EXP;
325 		break;
326 	}
327 	mutex_unlock(&conn->sess->cmdsn_mutex);
328 
329 	if (reject)
330 		iscsit_reject_cmd(cmd, reason, buf);
331 
332 	return ret;
333 }
334 EXPORT_SYMBOL(iscsit_sequence_cmd);
335 
336 int iscsit_check_unsolicited_dataout(struct iscsit_cmd *cmd, unsigned char *buf)
337 {
338 	struct iscsit_conn *conn = cmd->conn;
339 	struct se_cmd *se_cmd = &cmd->se_cmd;
340 	struct iscsi_data *hdr = (struct iscsi_data *) buf;
341 	u32 payload_length = ntoh24(hdr->dlength);
342 
343 	if (conn->sess->sess_ops->InitialR2T) {
344 		pr_err("Received unexpected unsolicited data"
345 			" while InitialR2T=Yes, protocol error.\n");
346 		transport_send_check_condition_and_sense(se_cmd,
347 				TCM_UNEXPECTED_UNSOLICITED_DATA, 0);
348 		return -1;
349 	}
350 
351 	if ((cmd->first_burst_len + payload_length) >
352 	     conn->sess->sess_ops->FirstBurstLength) {
353 		pr_err("Total %u bytes exceeds FirstBurstLength: %u"
354 			" for this Unsolicited DataOut Burst.\n",
355 			(cmd->first_burst_len + payload_length),
356 				conn->sess->sess_ops->FirstBurstLength);
357 		transport_send_check_condition_and_sense(se_cmd,
358 				TCM_INCORRECT_AMOUNT_OF_DATA, 0);
359 		return -1;
360 	}
361 
362 	if (!(hdr->flags & ISCSI_FLAG_CMD_FINAL))
363 		return 0;
364 
365 	if (((cmd->first_burst_len + payload_length) != cmd->se_cmd.data_length) &&
366 	    ((cmd->first_burst_len + payload_length) !=
367 	      conn->sess->sess_ops->FirstBurstLength)) {
368 		pr_err("Unsolicited non-immediate data received %u"
369 			" does not equal FirstBurstLength: %u, and does"
370 			" not equal ExpXferLen %u.\n",
371 			(cmd->first_burst_len + payload_length),
372 			conn->sess->sess_ops->FirstBurstLength, cmd->se_cmd.data_length);
373 		transport_send_check_condition_and_sense(se_cmd,
374 				TCM_INCORRECT_AMOUNT_OF_DATA, 0);
375 		return -1;
376 	}
377 	return 0;
378 }
379 
380 struct iscsit_cmd *iscsit_find_cmd_from_itt(
381 	struct iscsit_conn *conn,
382 	itt_t init_task_tag)
383 {
384 	struct iscsit_cmd *cmd;
385 
386 	spin_lock_bh(&conn->cmd_lock);
387 	list_for_each_entry(cmd, &conn->conn_cmd_list, i_conn_node) {
388 		if (cmd->init_task_tag == init_task_tag) {
389 			spin_unlock_bh(&conn->cmd_lock);
390 			return cmd;
391 		}
392 	}
393 	spin_unlock_bh(&conn->cmd_lock);
394 
395 	pr_err("Unable to locate ITT: 0x%08x on CID: %hu",
396 			init_task_tag, conn->cid);
397 	return NULL;
398 }
399 EXPORT_SYMBOL(iscsit_find_cmd_from_itt);
400 
401 struct iscsit_cmd *iscsit_find_cmd_from_itt_or_dump(
402 	struct iscsit_conn *conn,
403 	itt_t init_task_tag,
404 	u32 length)
405 {
406 	struct iscsit_cmd *cmd;
407 
408 	spin_lock_bh(&conn->cmd_lock);
409 	list_for_each_entry(cmd, &conn->conn_cmd_list, i_conn_node) {
410 		if (cmd->cmd_flags & ICF_GOT_LAST_DATAOUT)
411 			continue;
412 		if (cmd->init_task_tag == init_task_tag) {
413 			spin_unlock_bh(&conn->cmd_lock);
414 			return cmd;
415 		}
416 	}
417 	spin_unlock_bh(&conn->cmd_lock);
418 
419 	pr_err("Unable to locate ITT: 0x%08x on CID: %hu,"
420 			" dumping payload\n", init_task_tag, conn->cid);
421 	if (length)
422 		iscsit_dump_data_payload(conn, length, 1);
423 
424 	return NULL;
425 }
426 EXPORT_SYMBOL(iscsit_find_cmd_from_itt_or_dump);
427 
428 struct iscsit_cmd *iscsit_find_cmd_from_ttt(
429 	struct iscsit_conn *conn,
430 	u32 targ_xfer_tag)
431 {
432 	struct iscsit_cmd *cmd = NULL;
433 
434 	spin_lock_bh(&conn->cmd_lock);
435 	list_for_each_entry(cmd, &conn->conn_cmd_list, i_conn_node) {
436 		if (cmd->targ_xfer_tag == targ_xfer_tag) {
437 			spin_unlock_bh(&conn->cmd_lock);
438 			return cmd;
439 		}
440 	}
441 	spin_unlock_bh(&conn->cmd_lock);
442 
443 	pr_err("Unable to locate TTT: 0x%08x on CID: %hu\n",
444 			targ_xfer_tag, conn->cid);
445 	return NULL;
446 }
447 
448 int iscsit_find_cmd_for_recovery(
449 	struct iscsit_session *sess,
450 	struct iscsit_cmd **cmd_ptr,
451 	struct iscsi_conn_recovery **cr_ptr,
452 	itt_t init_task_tag)
453 {
454 	struct iscsit_cmd *cmd = NULL;
455 	struct iscsi_conn_recovery *cr;
456 	/*
457 	 * Scan through the inactive connection recovery list's command list.
458 	 * If init_task_tag matches the command is still alligent.
459 	 */
460 	spin_lock(&sess->cr_i_lock);
461 	list_for_each_entry(cr, &sess->cr_inactive_list, cr_list) {
462 		spin_lock(&cr->conn_recovery_cmd_lock);
463 		list_for_each_entry(cmd, &cr->conn_recovery_cmd_list, i_conn_node) {
464 			if (cmd->init_task_tag == init_task_tag) {
465 				spin_unlock(&cr->conn_recovery_cmd_lock);
466 				spin_unlock(&sess->cr_i_lock);
467 
468 				*cr_ptr = cr;
469 				*cmd_ptr = cmd;
470 				return -2;
471 			}
472 		}
473 		spin_unlock(&cr->conn_recovery_cmd_lock);
474 	}
475 	spin_unlock(&sess->cr_i_lock);
476 	/*
477 	 * Scan through the active connection recovery list's command list.
478 	 * If init_task_tag matches the command is ready to be reassigned.
479 	 */
480 	spin_lock(&sess->cr_a_lock);
481 	list_for_each_entry(cr, &sess->cr_active_list, cr_list) {
482 		spin_lock(&cr->conn_recovery_cmd_lock);
483 		list_for_each_entry(cmd, &cr->conn_recovery_cmd_list, i_conn_node) {
484 			if (cmd->init_task_tag == init_task_tag) {
485 				spin_unlock(&cr->conn_recovery_cmd_lock);
486 				spin_unlock(&sess->cr_a_lock);
487 
488 				*cr_ptr = cr;
489 				*cmd_ptr = cmd;
490 				return 0;
491 			}
492 		}
493 		spin_unlock(&cr->conn_recovery_cmd_lock);
494 	}
495 	spin_unlock(&sess->cr_a_lock);
496 
497 	return -1;
498 }
499 
500 void iscsit_add_cmd_to_immediate_queue(
501 	struct iscsit_cmd *cmd,
502 	struct iscsit_conn *conn,
503 	u8 state)
504 {
505 	struct iscsi_queue_req *qr;
506 
507 	qr = kmem_cache_zalloc(lio_qr_cache, GFP_ATOMIC);
508 	if (!qr) {
509 		pr_err("Unable to allocate memory for"
510 				" struct iscsi_queue_req\n");
511 		return;
512 	}
513 	INIT_LIST_HEAD(&qr->qr_list);
514 	qr->cmd = cmd;
515 	qr->state = state;
516 
517 	spin_lock_bh(&conn->immed_queue_lock);
518 	list_add_tail(&qr->qr_list, &conn->immed_queue_list);
519 	atomic_inc(&cmd->immed_queue_count);
520 	atomic_set(&conn->check_immediate_queue, 1);
521 	spin_unlock_bh(&conn->immed_queue_lock);
522 
523 	wake_up(&conn->queues_wq);
524 }
525 EXPORT_SYMBOL(iscsit_add_cmd_to_immediate_queue);
526 
527 struct iscsi_queue_req *iscsit_get_cmd_from_immediate_queue(struct iscsit_conn *conn)
528 {
529 	struct iscsi_queue_req *qr;
530 
531 	spin_lock_bh(&conn->immed_queue_lock);
532 	if (list_empty(&conn->immed_queue_list)) {
533 		spin_unlock_bh(&conn->immed_queue_lock);
534 		return NULL;
535 	}
536 	qr = list_first_entry(&conn->immed_queue_list,
537 			      struct iscsi_queue_req, qr_list);
538 
539 	list_del(&qr->qr_list);
540 	if (qr->cmd)
541 		atomic_dec(&qr->cmd->immed_queue_count);
542 	spin_unlock_bh(&conn->immed_queue_lock);
543 
544 	return qr;
545 }
546 
547 static void iscsit_remove_cmd_from_immediate_queue(
548 	struct iscsit_cmd *cmd,
549 	struct iscsit_conn *conn)
550 {
551 	struct iscsi_queue_req *qr, *qr_tmp;
552 
553 	spin_lock_bh(&conn->immed_queue_lock);
554 	if (!atomic_read(&cmd->immed_queue_count)) {
555 		spin_unlock_bh(&conn->immed_queue_lock);
556 		return;
557 	}
558 
559 	list_for_each_entry_safe(qr, qr_tmp, &conn->immed_queue_list, qr_list) {
560 		if (qr->cmd != cmd)
561 			continue;
562 
563 		atomic_dec(&qr->cmd->immed_queue_count);
564 		list_del(&qr->qr_list);
565 		kmem_cache_free(lio_qr_cache, qr);
566 	}
567 	spin_unlock_bh(&conn->immed_queue_lock);
568 
569 	if (atomic_read(&cmd->immed_queue_count)) {
570 		pr_err("ITT: 0x%08x immed_queue_count: %d\n",
571 			cmd->init_task_tag,
572 			atomic_read(&cmd->immed_queue_count));
573 	}
574 }
575 
576 int iscsit_add_cmd_to_response_queue(
577 	struct iscsit_cmd *cmd,
578 	struct iscsit_conn *conn,
579 	u8 state)
580 {
581 	struct iscsi_queue_req *qr;
582 
583 	qr = kmem_cache_zalloc(lio_qr_cache, GFP_ATOMIC);
584 	if (!qr) {
585 		pr_err("Unable to allocate memory for"
586 			" struct iscsi_queue_req\n");
587 		return -ENOMEM;
588 	}
589 	INIT_LIST_HEAD(&qr->qr_list);
590 	qr->cmd = cmd;
591 	qr->state = state;
592 
593 	spin_lock_bh(&conn->response_queue_lock);
594 	list_add_tail(&qr->qr_list, &conn->response_queue_list);
595 	atomic_inc(&cmd->response_queue_count);
596 	spin_unlock_bh(&conn->response_queue_lock);
597 
598 	wake_up(&conn->queues_wq);
599 	return 0;
600 }
601 
602 struct iscsi_queue_req *iscsit_get_cmd_from_response_queue(struct iscsit_conn *conn)
603 {
604 	struct iscsi_queue_req *qr;
605 
606 	spin_lock_bh(&conn->response_queue_lock);
607 	if (list_empty(&conn->response_queue_list)) {
608 		spin_unlock_bh(&conn->response_queue_lock);
609 		return NULL;
610 	}
611 
612 	qr = list_first_entry(&conn->response_queue_list,
613 			      struct iscsi_queue_req, qr_list);
614 
615 	list_del(&qr->qr_list);
616 	if (qr->cmd)
617 		atomic_dec(&qr->cmd->response_queue_count);
618 	spin_unlock_bh(&conn->response_queue_lock);
619 
620 	return qr;
621 }
622 
623 static void iscsit_remove_cmd_from_response_queue(
624 	struct iscsit_cmd *cmd,
625 	struct iscsit_conn *conn)
626 {
627 	struct iscsi_queue_req *qr, *qr_tmp;
628 
629 	spin_lock_bh(&conn->response_queue_lock);
630 	if (!atomic_read(&cmd->response_queue_count)) {
631 		spin_unlock_bh(&conn->response_queue_lock);
632 		return;
633 	}
634 
635 	list_for_each_entry_safe(qr, qr_tmp, &conn->response_queue_list,
636 				qr_list) {
637 		if (qr->cmd != cmd)
638 			continue;
639 
640 		atomic_dec(&qr->cmd->response_queue_count);
641 		list_del(&qr->qr_list);
642 		kmem_cache_free(lio_qr_cache, qr);
643 	}
644 	spin_unlock_bh(&conn->response_queue_lock);
645 
646 	if (atomic_read(&cmd->response_queue_count)) {
647 		pr_err("ITT: 0x%08x response_queue_count: %d\n",
648 			cmd->init_task_tag,
649 			atomic_read(&cmd->response_queue_count));
650 	}
651 }
652 
653 bool iscsit_conn_all_queues_empty(struct iscsit_conn *conn)
654 {
655 	bool empty;
656 
657 	spin_lock_bh(&conn->immed_queue_lock);
658 	empty = list_empty(&conn->immed_queue_list);
659 	spin_unlock_bh(&conn->immed_queue_lock);
660 
661 	if (!empty)
662 		return empty;
663 
664 	spin_lock_bh(&conn->response_queue_lock);
665 	empty = list_empty(&conn->response_queue_list);
666 	spin_unlock_bh(&conn->response_queue_lock);
667 
668 	return empty;
669 }
670 
671 void iscsit_free_queue_reqs_for_conn(struct iscsit_conn *conn)
672 {
673 	struct iscsi_queue_req *qr, *qr_tmp;
674 
675 	spin_lock_bh(&conn->immed_queue_lock);
676 	list_for_each_entry_safe(qr, qr_tmp, &conn->immed_queue_list, qr_list) {
677 		list_del(&qr->qr_list);
678 		if (qr->cmd)
679 			atomic_dec(&qr->cmd->immed_queue_count);
680 
681 		kmem_cache_free(lio_qr_cache, qr);
682 	}
683 	spin_unlock_bh(&conn->immed_queue_lock);
684 
685 	spin_lock_bh(&conn->response_queue_lock);
686 	list_for_each_entry_safe(qr, qr_tmp, &conn->response_queue_list,
687 			qr_list) {
688 		list_del(&qr->qr_list);
689 		if (qr->cmd)
690 			atomic_dec(&qr->cmd->response_queue_count);
691 
692 		kmem_cache_free(lio_qr_cache, qr);
693 	}
694 	spin_unlock_bh(&conn->response_queue_lock);
695 }
696 
697 void iscsit_release_cmd(struct iscsit_cmd *cmd)
698 {
699 	struct iscsit_session *sess;
700 	struct se_cmd *se_cmd = &cmd->se_cmd;
701 
702 	WARN_ON(!list_empty(&cmd->i_conn_node));
703 
704 	if (cmd->conn)
705 		sess = cmd->conn->sess;
706 	else
707 		sess = cmd->sess;
708 
709 	BUG_ON(!sess || !sess->se_sess);
710 
711 	kfree(cmd->buf_ptr);
712 	kfree(cmd->pdu_list);
713 	kfree(cmd->seq_list);
714 	kfree(cmd->tmr_req);
715 	kfree(cmd->overflow_buf);
716 	kfree(cmd->iov_data);
717 	kfree(cmd->text_in_ptr);
718 
719 	target_free_tag(sess->se_sess, se_cmd);
720 }
721 EXPORT_SYMBOL(iscsit_release_cmd);
722 
723 void __iscsit_free_cmd(struct iscsit_cmd *cmd, bool check_queues)
724 {
725 	struct iscsit_conn *conn = cmd->conn;
726 
727 	WARN_ON(!list_empty(&cmd->i_conn_node));
728 
729 	if (cmd->data_direction == DMA_TO_DEVICE) {
730 		iscsit_stop_dataout_timer(cmd);
731 		iscsit_free_r2ts_from_list(cmd);
732 	}
733 	if (cmd->data_direction == DMA_FROM_DEVICE)
734 		iscsit_free_all_datain_reqs(cmd);
735 
736 	if (conn && check_queues) {
737 		iscsit_remove_cmd_from_immediate_queue(cmd, conn);
738 		iscsit_remove_cmd_from_response_queue(cmd, conn);
739 	}
740 
741 	if (conn && conn->conn_transport->iscsit_unmap_cmd)
742 		conn->conn_transport->iscsit_unmap_cmd(conn, cmd);
743 }
744 
745 void iscsit_free_cmd(struct iscsit_cmd *cmd, bool shutdown)
746 {
747 	struct se_cmd *se_cmd = cmd->se_cmd.se_tfo ? &cmd->se_cmd : NULL;
748 	int rc;
749 
750 	WARN_ON(!list_empty(&cmd->i_conn_node));
751 
752 	__iscsit_free_cmd(cmd, shutdown);
753 	if (se_cmd) {
754 		rc = transport_generic_free_cmd(se_cmd, shutdown);
755 		if (!rc && shutdown && se_cmd->se_sess) {
756 			__iscsit_free_cmd(cmd, shutdown);
757 			target_put_sess_cmd(se_cmd);
758 		}
759 	} else {
760 		iscsit_release_cmd(cmd);
761 	}
762 }
763 EXPORT_SYMBOL(iscsit_free_cmd);
764 
765 bool iscsit_check_session_usage_count(struct iscsit_session *sess,
766 				      bool can_sleep)
767 {
768 	spin_lock_bh(&sess->session_usage_lock);
769 	if (sess->session_usage_count != 0) {
770 		sess->session_waiting_on_uc = 1;
771 		spin_unlock_bh(&sess->session_usage_lock);
772 		if (!can_sleep)
773 			return true;
774 
775 		wait_for_completion(&sess->session_waiting_on_uc_comp);
776 		return false;
777 	}
778 	spin_unlock_bh(&sess->session_usage_lock);
779 
780 	return false;
781 }
782 
783 void iscsit_dec_session_usage_count(struct iscsit_session *sess)
784 {
785 	spin_lock_bh(&sess->session_usage_lock);
786 	sess->session_usage_count--;
787 
788 	if (!sess->session_usage_count && sess->session_waiting_on_uc)
789 		complete(&sess->session_waiting_on_uc_comp);
790 
791 	spin_unlock_bh(&sess->session_usage_lock);
792 }
793 
794 void iscsit_inc_session_usage_count(struct iscsit_session *sess)
795 {
796 	spin_lock_bh(&sess->session_usage_lock);
797 	sess->session_usage_count++;
798 	spin_unlock_bh(&sess->session_usage_lock);
799 }
800 
801 struct iscsit_conn *iscsit_get_conn_from_cid(struct iscsit_session *sess, u16 cid)
802 {
803 	struct iscsit_conn *conn;
804 
805 	spin_lock_bh(&sess->conn_lock);
806 	list_for_each_entry(conn, &sess->sess_conn_list, conn_list) {
807 		if ((conn->cid == cid) &&
808 		    (conn->conn_state == TARG_CONN_STATE_LOGGED_IN)) {
809 			iscsit_inc_conn_usage_count(conn);
810 			spin_unlock_bh(&sess->conn_lock);
811 			return conn;
812 		}
813 	}
814 	spin_unlock_bh(&sess->conn_lock);
815 
816 	return NULL;
817 }
818 
819 struct iscsit_conn *iscsit_get_conn_from_cid_rcfr(struct iscsit_session *sess, u16 cid)
820 {
821 	struct iscsit_conn *conn;
822 
823 	spin_lock_bh(&sess->conn_lock);
824 	list_for_each_entry(conn, &sess->sess_conn_list, conn_list) {
825 		if (conn->cid == cid) {
826 			iscsit_inc_conn_usage_count(conn);
827 			spin_lock(&conn->state_lock);
828 			atomic_set(&conn->connection_wait_rcfr, 1);
829 			spin_unlock(&conn->state_lock);
830 			spin_unlock_bh(&sess->conn_lock);
831 			return conn;
832 		}
833 	}
834 	spin_unlock_bh(&sess->conn_lock);
835 
836 	return NULL;
837 }
838 
839 void iscsit_check_conn_usage_count(struct iscsit_conn *conn)
840 {
841 	spin_lock_bh(&conn->conn_usage_lock);
842 	if (conn->conn_usage_count != 0) {
843 		conn->conn_waiting_on_uc = 1;
844 		spin_unlock_bh(&conn->conn_usage_lock);
845 
846 		wait_for_completion(&conn->conn_waiting_on_uc_comp);
847 		return;
848 	}
849 	spin_unlock_bh(&conn->conn_usage_lock);
850 }
851 
852 void iscsit_dec_conn_usage_count(struct iscsit_conn *conn)
853 {
854 	spin_lock_bh(&conn->conn_usage_lock);
855 	conn->conn_usage_count--;
856 
857 	if (!conn->conn_usage_count && conn->conn_waiting_on_uc)
858 		complete(&conn->conn_waiting_on_uc_comp);
859 
860 	spin_unlock_bh(&conn->conn_usage_lock);
861 }
862 
863 void iscsit_inc_conn_usage_count(struct iscsit_conn *conn)
864 {
865 	spin_lock_bh(&conn->conn_usage_lock);
866 	conn->conn_usage_count++;
867 	spin_unlock_bh(&conn->conn_usage_lock);
868 }
869 
870 static int iscsit_add_nopin(struct iscsit_conn *conn, int want_response)
871 {
872 	u8 state;
873 	struct iscsit_cmd *cmd;
874 
875 	cmd = iscsit_allocate_cmd(conn, TASK_RUNNING);
876 	if (!cmd)
877 		return -1;
878 
879 	cmd->iscsi_opcode = ISCSI_OP_NOOP_IN;
880 	state = (want_response) ? ISTATE_SEND_NOPIN_WANT_RESPONSE :
881 				ISTATE_SEND_NOPIN_NO_RESPONSE;
882 	cmd->init_task_tag = RESERVED_ITT;
883 	cmd->targ_xfer_tag = (want_response) ?
884 			     session_get_next_ttt(conn->sess) : 0xFFFFFFFF;
885 	spin_lock_bh(&conn->cmd_lock);
886 	list_add_tail(&cmd->i_conn_node, &conn->conn_cmd_list);
887 	spin_unlock_bh(&conn->cmd_lock);
888 
889 	if (want_response)
890 		iscsit_start_nopin_response_timer(conn);
891 	iscsit_add_cmd_to_immediate_queue(cmd, conn, state);
892 
893 	return 0;
894 }
895 
896 void iscsit_handle_nopin_response_timeout(struct timer_list *t)
897 {
898 	struct iscsit_conn *conn = from_timer(conn, t, nopin_response_timer);
899 	struct iscsit_session *sess = conn->sess;
900 
901 	iscsit_inc_conn_usage_count(conn);
902 
903 	spin_lock_bh(&conn->nopin_timer_lock);
904 	if (conn->nopin_response_timer_flags & ISCSI_TF_STOP) {
905 		spin_unlock_bh(&conn->nopin_timer_lock);
906 		iscsit_dec_conn_usage_count(conn);
907 		return;
908 	}
909 
910 	pr_err("Did not receive response to NOPIN on CID: %hu, failing"
911 		" connection for I_T Nexus %s,i,0x%6phN,%s,t,0x%02x\n",
912 		conn->cid, sess->sess_ops->InitiatorName, sess->isid,
913 		sess->tpg->tpg_tiqn->tiqn, (u32)sess->tpg->tpgt);
914 	conn->nopin_response_timer_flags &= ~ISCSI_TF_RUNNING;
915 	spin_unlock_bh(&conn->nopin_timer_lock);
916 
917 	iscsit_fill_cxn_timeout_err_stats(sess);
918 	iscsit_cause_connection_reinstatement(conn, 0);
919 	iscsit_dec_conn_usage_count(conn);
920 }
921 
922 void iscsit_mod_nopin_response_timer(struct iscsit_conn *conn)
923 {
924 	struct iscsit_session *sess = conn->sess;
925 	struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess);
926 
927 	spin_lock_bh(&conn->nopin_timer_lock);
928 	if (!(conn->nopin_response_timer_flags & ISCSI_TF_RUNNING)) {
929 		spin_unlock_bh(&conn->nopin_timer_lock);
930 		return;
931 	}
932 
933 	mod_timer(&conn->nopin_response_timer,
934 		(get_jiffies_64() + na->nopin_response_timeout * HZ));
935 	spin_unlock_bh(&conn->nopin_timer_lock);
936 }
937 
938 void iscsit_start_nopin_response_timer(struct iscsit_conn *conn)
939 {
940 	struct iscsit_session *sess = conn->sess;
941 	struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess);
942 
943 	spin_lock_bh(&conn->nopin_timer_lock);
944 	if (conn->nopin_response_timer_flags & ISCSI_TF_RUNNING) {
945 		spin_unlock_bh(&conn->nopin_timer_lock);
946 		return;
947 	}
948 
949 	conn->nopin_response_timer_flags &= ~ISCSI_TF_STOP;
950 	conn->nopin_response_timer_flags |= ISCSI_TF_RUNNING;
951 	mod_timer(&conn->nopin_response_timer,
952 		  jiffies + na->nopin_response_timeout * HZ);
953 
954 	pr_debug("Started NOPIN Response Timer on CID: %d to %u"
955 		" seconds\n", conn->cid, na->nopin_response_timeout);
956 	spin_unlock_bh(&conn->nopin_timer_lock);
957 }
958 
959 void iscsit_stop_nopin_response_timer(struct iscsit_conn *conn)
960 {
961 	spin_lock_bh(&conn->nopin_timer_lock);
962 	if (!(conn->nopin_response_timer_flags & ISCSI_TF_RUNNING)) {
963 		spin_unlock_bh(&conn->nopin_timer_lock);
964 		return;
965 	}
966 	conn->nopin_response_timer_flags |= ISCSI_TF_STOP;
967 	spin_unlock_bh(&conn->nopin_timer_lock);
968 
969 	del_timer_sync(&conn->nopin_response_timer);
970 
971 	spin_lock_bh(&conn->nopin_timer_lock);
972 	conn->nopin_response_timer_flags &= ~ISCSI_TF_RUNNING;
973 	spin_unlock_bh(&conn->nopin_timer_lock);
974 }
975 
976 void iscsit_handle_nopin_timeout(struct timer_list *t)
977 {
978 	struct iscsit_conn *conn = from_timer(conn, t, nopin_timer);
979 
980 	iscsit_inc_conn_usage_count(conn);
981 
982 	spin_lock_bh(&conn->nopin_timer_lock);
983 	if (conn->nopin_timer_flags & ISCSI_TF_STOP) {
984 		spin_unlock_bh(&conn->nopin_timer_lock);
985 		iscsit_dec_conn_usage_count(conn);
986 		return;
987 	}
988 	conn->nopin_timer_flags &= ~ISCSI_TF_RUNNING;
989 	spin_unlock_bh(&conn->nopin_timer_lock);
990 
991 	iscsit_add_nopin(conn, 1);
992 	iscsit_dec_conn_usage_count(conn);
993 }
994 
995 void __iscsit_start_nopin_timer(struct iscsit_conn *conn)
996 {
997 	struct iscsit_session *sess = conn->sess;
998 	struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess);
999 
1000 	lockdep_assert_held(&conn->nopin_timer_lock);
1001 
1002 	/*
1003 	* NOPIN timeout is disabled.
1004 	 */
1005 	if (!na->nopin_timeout)
1006 		return;
1007 
1008 	if (conn->nopin_timer_flags & ISCSI_TF_RUNNING)
1009 		return;
1010 
1011 	conn->nopin_timer_flags &= ~ISCSI_TF_STOP;
1012 	conn->nopin_timer_flags |= ISCSI_TF_RUNNING;
1013 	mod_timer(&conn->nopin_timer, jiffies + na->nopin_timeout * HZ);
1014 
1015 	pr_debug("Started NOPIN Timer on CID: %d at %u second"
1016 		" interval\n", conn->cid, na->nopin_timeout);
1017 }
1018 
1019 void iscsit_start_nopin_timer(struct iscsit_conn *conn)
1020 {
1021 	spin_lock_bh(&conn->nopin_timer_lock);
1022 	__iscsit_start_nopin_timer(conn);
1023 	spin_unlock_bh(&conn->nopin_timer_lock);
1024 }
1025 
1026 void iscsit_stop_nopin_timer(struct iscsit_conn *conn)
1027 {
1028 	spin_lock_bh(&conn->nopin_timer_lock);
1029 	if (!(conn->nopin_timer_flags & ISCSI_TF_RUNNING)) {
1030 		spin_unlock_bh(&conn->nopin_timer_lock);
1031 		return;
1032 	}
1033 	conn->nopin_timer_flags |= ISCSI_TF_STOP;
1034 	spin_unlock_bh(&conn->nopin_timer_lock);
1035 
1036 	del_timer_sync(&conn->nopin_timer);
1037 
1038 	spin_lock_bh(&conn->nopin_timer_lock);
1039 	conn->nopin_timer_flags &= ~ISCSI_TF_RUNNING;
1040 	spin_unlock_bh(&conn->nopin_timer_lock);
1041 }
1042 
1043 void iscsit_login_timeout(struct timer_list *t)
1044 {
1045 	struct iscsit_conn *conn = from_timer(conn, t, login_timer);
1046 	struct iscsi_login *login = conn->login;
1047 
1048 	pr_debug("Entering iscsi_target_login_timeout >>>>>>>>>>>>>>>>>>>\n");
1049 
1050 	spin_lock_bh(&conn->login_timer_lock);
1051 	login->login_failed = 1;
1052 
1053 	if (conn->login_kworker) {
1054 		pr_debug("Sending SIGINT to conn->login_kworker %s/%d\n",
1055 			 conn->login_kworker->comm, conn->login_kworker->pid);
1056 		send_sig(SIGINT, conn->login_kworker, 1);
1057 	} else {
1058 		schedule_delayed_work(&conn->login_work, 0);
1059 	}
1060 	spin_unlock_bh(&conn->login_timer_lock);
1061 }
1062 
1063 void iscsit_start_login_timer(struct iscsit_conn *conn, struct task_struct *kthr)
1064 {
1065 	pr_debug("Login timer started\n");
1066 
1067 	conn->login_kworker = kthr;
1068 	mod_timer(&conn->login_timer, jiffies + TA_LOGIN_TIMEOUT * HZ);
1069 }
1070 
1071 int iscsit_set_login_timer_kworker(struct iscsit_conn *conn, struct task_struct *kthr)
1072 {
1073 	struct iscsi_login *login = conn->login;
1074 	int ret = 0;
1075 
1076 	spin_lock_bh(&conn->login_timer_lock);
1077 	if (login->login_failed) {
1078 		/* The timer has already expired */
1079 		ret = -1;
1080 	} else {
1081 		conn->login_kworker = kthr;
1082 	}
1083 	spin_unlock_bh(&conn->login_timer_lock);
1084 
1085 	return ret;
1086 }
1087 
1088 void iscsit_stop_login_timer(struct iscsit_conn *conn)
1089 {
1090 	pr_debug("Login timer stopped\n");
1091 	timer_delete_sync(&conn->login_timer);
1092 }
1093 
1094 int iscsit_send_tx_data(
1095 	struct iscsit_cmd *cmd,
1096 	struct iscsit_conn *conn,
1097 	int use_misc)
1098 {
1099 	int tx_sent, tx_size;
1100 	u32 iov_count;
1101 	struct kvec *iov;
1102 
1103 send_data:
1104 	tx_size = cmd->tx_size;
1105 
1106 	if (!use_misc) {
1107 		iov = &cmd->iov_data[0];
1108 		iov_count = cmd->iov_data_count;
1109 	} else {
1110 		iov = &cmd->iov_misc[0];
1111 		iov_count = cmd->iov_misc_count;
1112 	}
1113 
1114 	tx_sent = tx_data(conn, &iov[0], iov_count, tx_size);
1115 	if (tx_size != tx_sent) {
1116 		if (tx_sent == -EAGAIN) {
1117 			pr_err("tx_data() returned -EAGAIN\n");
1118 			goto send_data;
1119 		} else
1120 			return -1;
1121 	}
1122 	cmd->tx_size = 0;
1123 
1124 	return 0;
1125 }
1126 
1127 int iscsit_fe_sendpage_sg(
1128 	struct iscsit_cmd *cmd,
1129 	struct iscsit_conn *conn)
1130 {
1131 	struct scatterlist *sg = cmd->first_data_sg;
1132 	struct bio_vec bvec;
1133 	struct msghdr msghdr = { .msg_flags = MSG_SPLICE_PAGES,	};
1134 	struct kvec iov;
1135 	u32 tx_hdr_size, data_len;
1136 	u32 offset = cmd->first_data_sg_off;
1137 	int tx_sent, iov_off;
1138 
1139 send_hdr:
1140 	tx_hdr_size = ISCSI_HDR_LEN;
1141 	if (conn->conn_ops->HeaderDigest)
1142 		tx_hdr_size += ISCSI_CRC_LEN;
1143 
1144 	iov.iov_base = cmd->pdu;
1145 	iov.iov_len = tx_hdr_size;
1146 
1147 	tx_sent = tx_data(conn, &iov, 1, tx_hdr_size);
1148 	if (tx_hdr_size != tx_sent) {
1149 		if (tx_sent == -EAGAIN) {
1150 			pr_err("tx_data() returned -EAGAIN\n");
1151 			goto send_hdr;
1152 		}
1153 		return -1;
1154 	}
1155 
1156 	data_len = cmd->tx_size - tx_hdr_size - cmd->padding;
1157 	/*
1158 	 * Set iov_off used by padding and data digest tx_data() calls below
1159 	 * in order to determine proper offset into cmd->iov_data[]
1160 	 */
1161 	if (conn->conn_ops->DataDigest) {
1162 		data_len -= ISCSI_CRC_LEN;
1163 		if (cmd->padding)
1164 			iov_off = (cmd->iov_data_count - 2);
1165 		else
1166 			iov_off = (cmd->iov_data_count - 1);
1167 	} else {
1168 		iov_off = (cmd->iov_data_count - 1);
1169 	}
1170 	/*
1171 	 * Perform sendpage() for each page in the scatterlist
1172 	 */
1173 	while (data_len) {
1174 		u32 space = (sg->length - offset);
1175 		u32 sub_len = min_t(u32, data_len, space);
1176 send_pg:
1177 		bvec_set_page(&bvec, sg_page(sg), sub_len, sg->offset + offset);
1178 		iov_iter_bvec(&msghdr.msg_iter, ITER_SOURCE, &bvec, 1, sub_len);
1179 
1180 		tx_sent = conn->sock->ops->sendmsg(conn->sock, &msghdr,
1181 						   sub_len);
1182 		if (tx_sent != sub_len) {
1183 			if (tx_sent == -EAGAIN) {
1184 				pr_err("sendmsg/splice returned -EAGAIN\n");
1185 				goto send_pg;
1186 			}
1187 
1188 			pr_err("sendmsg/splice failure: %d\n", tx_sent);
1189 			return -1;
1190 		}
1191 
1192 		data_len -= sub_len;
1193 		offset = 0;
1194 		sg = sg_next(sg);
1195 	}
1196 
1197 send_padding:
1198 	if (cmd->padding) {
1199 		struct kvec *iov_p = &cmd->iov_data[iov_off++];
1200 
1201 		tx_sent = tx_data(conn, iov_p, 1, cmd->padding);
1202 		if (cmd->padding != tx_sent) {
1203 			if (tx_sent == -EAGAIN) {
1204 				pr_err("tx_data() returned -EAGAIN\n");
1205 				goto send_padding;
1206 			}
1207 			return -1;
1208 		}
1209 	}
1210 
1211 send_datacrc:
1212 	if (conn->conn_ops->DataDigest) {
1213 		struct kvec *iov_d = &cmd->iov_data[iov_off];
1214 
1215 		tx_sent = tx_data(conn, iov_d, 1, ISCSI_CRC_LEN);
1216 		if (ISCSI_CRC_LEN != tx_sent) {
1217 			if (tx_sent == -EAGAIN) {
1218 				pr_err("tx_data() returned -EAGAIN\n");
1219 				goto send_datacrc;
1220 			}
1221 			return -1;
1222 		}
1223 	}
1224 
1225 	return 0;
1226 }
1227 
1228 /*
1229  *      This function is used for mainly sending a ISCSI_TARG_LOGIN_RSP PDU
1230  *      back to the Initiator when an expection condition occurs with the
1231  *      errors set in status_class and status_detail.
1232  *
1233  *      Parameters:     iSCSI Connection, Status Class, Status Detail.
1234  *      Returns:        0 on success, -1 on error.
1235  */
1236 int iscsit_tx_login_rsp(struct iscsit_conn *conn, u8 status_class, u8 status_detail)
1237 {
1238 	struct iscsi_login_rsp *hdr;
1239 	struct iscsi_login *login = conn->conn_login;
1240 
1241 	login->login_failed = 1;
1242 	iscsit_collect_login_stats(conn, status_class, status_detail);
1243 
1244 	memset(&login->rsp[0], 0, ISCSI_HDR_LEN);
1245 
1246 	hdr	= (struct iscsi_login_rsp *)&login->rsp[0];
1247 	hdr->opcode		= ISCSI_OP_LOGIN_RSP;
1248 	hdr->status_class	= status_class;
1249 	hdr->status_detail	= status_detail;
1250 	hdr->itt		= conn->login_itt;
1251 
1252 	return conn->conn_transport->iscsit_put_login_tx(conn, login, 0);
1253 }
1254 
1255 void iscsit_print_session_params(struct iscsit_session *sess)
1256 {
1257 	struct iscsit_conn *conn;
1258 
1259 	pr_debug("-----------------------------[Session Params for"
1260 		" SID: %u]-----------------------------\n", sess->sid);
1261 	spin_lock_bh(&sess->conn_lock);
1262 	list_for_each_entry(conn, &sess->sess_conn_list, conn_list)
1263 		iscsi_dump_conn_ops(conn->conn_ops);
1264 	spin_unlock_bh(&sess->conn_lock);
1265 
1266 	iscsi_dump_sess_ops(sess->sess_ops);
1267 }
1268 
1269 int rx_data(
1270 	struct iscsit_conn *conn,
1271 	struct kvec *iov,
1272 	int iov_count,
1273 	int data)
1274 {
1275 	int rx_loop = 0, total_rx = 0;
1276 	struct msghdr msg;
1277 
1278 	if (!conn || !conn->sock || !conn->conn_ops)
1279 		return -1;
1280 
1281 	memset(&msg, 0, sizeof(struct msghdr));
1282 	iov_iter_kvec(&msg.msg_iter, ITER_DEST, iov, iov_count, data);
1283 
1284 	while (msg_data_left(&msg)) {
1285 		rx_loop = sock_recvmsg(conn->sock, &msg, MSG_WAITALL);
1286 		if (rx_loop <= 0) {
1287 			pr_debug("rx_loop: %d total_rx: %d\n",
1288 				rx_loop, total_rx);
1289 			return rx_loop;
1290 		}
1291 		total_rx += rx_loop;
1292 		pr_debug("rx_loop: %d, total_rx: %d, data: %d\n",
1293 				rx_loop, total_rx, data);
1294 	}
1295 
1296 	return total_rx;
1297 }
1298 
1299 int tx_data(
1300 	struct iscsit_conn *conn,
1301 	struct kvec *iov,
1302 	int iov_count,
1303 	int data)
1304 {
1305 	struct msghdr msg;
1306 	int total_tx = 0;
1307 
1308 	if (!conn || !conn->sock || !conn->conn_ops)
1309 		return -1;
1310 
1311 	if (data <= 0) {
1312 		pr_err("Data length is: %d\n", data);
1313 		return -1;
1314 	}
1315 
1316 	memset(&msg, 0, sizeof(struct msghdr));
1317 
1318 	iov_iter_kvec(&msg.msg_iter, ITER_SOURCE, iov, iov_count, data);
1319 
1320 	while (msg_data_left(&msg)) {
1321 		int tx_loop = sock_sendmsg(conn->sock, &msg);
1322 		if (tx_loop <= 0) {
1323 			pr_debug("tx_loop: %d total_tx %d\n",
1324 				tx_loop, total_tx);
1325 			return tx_loop;
1326 		}
1327 		total_tx += tx_loop;
1328 		pr_debug("tx_loop: %d, total_tx: %d, data: %d\n",
1329 					tx_loop, total_tx, data);
1330 	}
1331 
1332 	return total_tx;
1333 }
1334 
1335 void iscsit_collect_login_stats(
1336 	struct iscsit_conn *conn,
1337 	u8 status_class,
1338 	u8 status_detail)
1339 {
1340 	struct iscsi_param *intrname = NULL;
1341 	struct iscsi_tiqn *tiqn;
1342 	struct iscsi_login_stats *ls;
1343 
1344 	tiqn = iscsit_snmp_get_tiqn(conn);
1345 	if (!tiqn)
1346 		return;
1347 
1348 	ls = &tiqn->login_stats;
1349 
1350 	spin_lock(&ls->lock);
1351 	if (status_class == ISCSI_STATUS_CLS_SUCCESS)
1352 		ls->accepts++;
1353 	else if (status_class == ISCSI_STATUS_CLS_REDIRECT) {
1354 		ls->redirects++;
1355 		ls->last_fail_type = ISCSI_LOGIN_FAIL_REDIRECT;
1356 	} else if ((status_class == ISCSI_STATUS_CLS_INITIATOR_ERR)  &&
1357 		 (status_detail == ISCSI_LOGIN_STATUS_AUTH_FAILED)) {
1358 		ls->authenticate_fails++;
1359 		ls->last_fail_type =  ISCSI_LOGIN_FAIL_AUTHENTICATE;
1360 	} else if ((status_class == ISCSI_STATUS_CLS_INITIATOR_ERR)  &&
1361 		 (status_detail == ISCSI_LOGIN_STATUS_TGT_FORBIDDEN)) {
1362 		ls->authorize_fails++;
1363 		ls->last_fail_type = ISCSI_LOGIN_FAIL_AUTHORIZE;
1364 	} else if ((status_class == ISCSI_STATUS_CLS_INITIATOR_ERR) &&
1365 		 (status_detail == ISCSI_LOGIN_STATUS_INIT_ERR)) {
1366 		ls->negotiate_fails++;
1367 		ls->last_fail_type = ISCSI_LOGIN_FAIL_NEGOTIATE;
1368 	} else {
1369 		ls->other_fails++;
1370 		ls->last_fail_type = ISCSI_LOGIN_FAIL_OTHER;
1371 	}
1372 
1373 	/* Save initiator name, ip address and time, if it is a failed login */
1374 	if (status_class != ISCSI_STATUS_CLS_SUCCESS) {
1375 		if (conn->param_list)
1376 			intrname = iscsi_find_param_from_key(INITIATORNAME,
1377 							     conn->param_list);
1378 		strscpy(ls->last_intr_fail_name,
1379 		       (intrname ? intrname->value : "Unknown"),
1380 		       sizeof(ls->last_intr_fail_name));
1381 
1382 		ls->last_intr_fail_ip_family = conn->login_family;
1383 
1384 		ls->last_intr_fail_sockaddr = conn->login_sockaddr;
1385 		ls->last_fail_time = get_jiffies_64();
1386 	}
1387 
1388 	spin_unlock(&ls->lock);
1389 }
1390 
1391 struct iscsi_tiqn *iscsit_snmp_get_tiqn(struct iscsit_conn *conn)
1392 {
1393 	struct iscsi_portal_group *tpg;
1394 
1395 	if (!conn)
1396 		return NULL;
1397 
1398 	tpg = conn->tpg;
1399 	if (!tpg)
1400 		return NULL;
1401 
1402 	if (!tpg->tpg_tiqn)
1403 		return NULL;
1404 
1405 	return tpg->tpg_tiqn;
1406 }
1407 
1408 void iscsit_fill_cxn_timeout_err_stats(struct iscsit_session *sess)
1409 {
1410 	struct iscsi_portal_group *tpg = sess->tpg;
1411 	struct iscsi_tiqn *tiqn = tpg->tpg_tiqn;
1412 
1413 	if (!tiqn)
1414 		return;
1415 
1416 	spin_lock_bh(&tiqn->sess_err_stats.lock);
1417 	strscpy(tiqn->sess_err_stats.last_sess_fail_rem_name,
1418 			sess->sess_ops->InitiatorName,
1419 			sizeof(tiqn->sess_err_stats.last_sess_fail_rem_name));
1420 	tiqn->sess_err_stats.last_sess_failure_type =
1421 			ISCSI_SESS_ERR_CXN_TIMEOUT;
1422 	tiqn->sess_err_stats.cxn_timeout_errors++;
1423 	atomic_long_inc(&sess->conn_timeout_errors);
1424 	spin_unlock_bh(&tiqn->sess_err_stats.lock);
1425 }
1426